Occurence And Transmission Of Airborne Escherichia Coli In Chicken House

Microorganisms and their Products in bioaerosol from animal houses can cause serious air pollution.They may also affect the health and the production capability of the animals and induce prevalence of aerosol infectious diseases.The polluted air in livestock farms is often associated with the outbreak of the epidemic diseases and the environmental problems.It is known that many airborne pathogen microorganisms,including viruses and bacteria,can spread over a large area through the air.bioaerosol disseminated from animal houses to their environments has been studied with an emphasis on total bacterium amount,pathogenic bacteria and antibiotic resistances of the bacteria or using ERIC-PCR in animal houses and their ambient air .It is can not get the enough evidence to prove the transmission of microorganism from animal houses to their surroundings. In order to get enough evidence to prove spread of microorganisms aerosol, useing E. coliJM109 strain marked with green fluorescent protein for the instructions. a model to estimate spread of the airborne microorganism was established in this study.Green fluorescent protein(GFP) is widely used in the study of prokaryote and eukaryote as new reporter gene.The green fluoreseence is excitated by UV or blue light.It is stable﹑high sensitive and it doesn't need substrates or helper factors.Since suceessfully expressed in Escherichia coli and Caenorhabditis elegans,GFP and other fluorescent proteins have been widely used for many studies.In this study,After Chicken drank E. coliJM109 strain marked with green fluorescent protein water. air samples,including fence and outside of the fence air (2 and 5 m as well as 10, 20 m away) of chicken house were collected using six-stage Andersen microbial samplers. E.coli JM109-pGFP concentrations (CFU/m3 air) collected from different sampling sites were calculated Through the E. coli JM109-pGFP obtained from different sampling sites the spreading of bioaerosol from animal houses to the ambient air was characterized. After Chicken drank E. coliJM109-pGFPculture medium chicken half an hour,they excreted feces containing E. coli JM109-pGFP,at the same time the isolated E. coli JM109-pGFP concentrations in fence air and outside sites of the(2 and 5 m as well as 10,20 m away) reached a new high,were 1.531×103﹑8.080×102﹑3.360×102﹑2.25×102﹑6.600×10 CFU/m3,but there were no significant difference between the fence and the outside sites of the fence (P>0.05).After 30hours,E. coli JM109-pGFP concentration is 7 CFU/m3,E. coli JM109-pGFP in other sites disappeared.After 36hours E. coli JM109-pGFPdisappeared in fence air.Our results suggested that E. coli JM109-pGFP isolated from cage air and outside of the cage air originated in the chicken feces and the microbiological aerosols in the chicken house were transmitted by air exchanging to the surroundings , so it could cause environmental microbiological pollution to some extents.